Argon is becoming increasingly more important for use in many industrial applications such as in the production of stainless steel, in the electronics industry, and in reactive metal production such as titanium processing.
Argon is generally produced by the cryogenic rectification of air. Air contains about 78 percent nitrogen, 21 percent oxygen and less than 1 percent argon. Because the argon concentration in air is relatively low, it has the highest per unit value of the major atmospheric gases. However, conventional cryogenic air separation processes can recover only about 70 percent of the argon in the feed air. Thus it is desirable to increase the recovery of argon produced by the cryogenic rectification of air.
Accordingly it is an object of this invention to provide a cryogenic rectification system which can produce argon with increased recovery.